BR112018014897B1 - INORGANIC PARTICULATE MATERIAL SUITABLE FOR USE IN POLYMERIC FILMS - Google Patents

Abstract

The present invention relates to an inorganic particulate material suitable for use in polymeric films, compositions such as polymeric films comprising the inorganic particulate materials, methods of producing said compositions, and the various uses of the inorganic particulate materials and compositions.

Description

TECHNICAL FIELD

[0001] The present invention generally relates to an inorganic particulate material (for example, an alkaline earth metal carbonate, such as calcium carbonate), suitable for use in polymeric compositions, for example, polymeric films, which can have high mineral loading. The present invention further relates to compositions comprising the inorganic particulate material, in particular polymers, such as polymeric films comprising the inorganic particulate material. The present invention also relates to the use of the inorganic particulate material in polymeric compositions, such as polymeric film, and methods of producing polymeric compositions, such as polymeric films comprising the inorganic particulate material. Certain embodiments of the present invention relate to breathable polymeric films (for example, films that allow the transmission of gas and vapours).

BACKGROUND OF THE INVENTION

[0002] Inorganic particulate materials, such as calcium carbonate, are used for numerous applications. One such use is the use in polymer compositions. The inorganic particulate material can be used as a filler (for example, to reduce the amount of polymer required in the composition, for example, to reduce the cost of the composition), or it can affect the properties of the polymer.

[0003] For example, inorganic particulate materials can be used in polymeric films. Such films, porous or non-porous, are manufactured for a number of consumer products, such as garbage bags, lining materials, or outer coverings in diapers, dressings, training pants, sanitary napkins, surgical gowns, and surgical supplements. . Polymeric films comprising polymer, inorganic particulate material, and optional additives, such as binding agent(s), or tackifying agent(s), can be formed by mixing (e.g., compounding) these components and then , forming the resulting composition into a film layer using any of a variety of film-making processes known to one skilled in the art (e.g., by casting, blowing, or extrusion). If the film is to be a porous, breathable film, the film can be stretched, uniaxially or biaxially, by any of the techniques well known in the art including hydraulics, rollers with grippers moving at different rates, and tensioners.

[0004] The nature and amount of inorganic particulate matter used in a polymeric film can influence the properties of the film, for example pore size (and therefore degree of breathability), strength, thickness and flexibility. The nature of the inorganic particulate matter can also influence how easily and quickly the film can be processed. Decreasing the particle size of the inorganic particulate material can allow thinner films to be produced. However, this can cause problems with rheology of the polymeric melts and processing of the polymeric films, for example, increasing the operating time. For example, decreasing the particle size of the inorganic particulate material can result in increased stress being applied to the casting as it emerges from the mold, which can, for example, increase the likelihood of developing holes in the casting.

[0005] Decreasing the particle size of inorganic particulate material can also cause processing problems in the formation of other polymer products, such as polymer fibers, for example, by increasing the viscosity of a polymer melt (for example, in high load loads). For example, swelling of the polymer melt as it emerges from a spinarette, causing material to build up in the mold which can create beading and failure of the nonwoven web.

[0006] The incorporation of inorganic particulate matter into the polymeric film, in particular at high loading levels and/or in thin films, may result in inorganic particulate matter being released from the film, and being deposited on the surface of the film (" scan"). This can, for example, be detrimental to the post-production converting process, for example during printing or laminating the films onto other structures (eg during diaper production).

[0007] It is therefore desirable to provide alternative and/or improved inorganic particulate materials that are suitable for use in polymer compositions such as polymeric films.

SUMMARY OF THE INVENTION

[0008] According to a first aspect of the present invention, there is provided an inorganic particulate material (a) having a d98 of less than about 11 µm or less than about 8 µm; and/or (b) comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 40 µm; and/or (c) comprising equal to or less than about 40% by weight of particles smaller than about 0.75 µm.

[0009] Thus, in a further aspect of the present invention, there is provided an inorganic particulate material having a d98 of less than about 11 µm, or less than about 8 µm, and comprising equal to or more than about of 3 ppm particles having a particle size equal to or greater than about 40 µm.

[0010] Accordingly, in a further aspect of the present invention, there is provided an inorganic particulate material comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 40 µm, and equal to or less than about 40% by weight of particles smaller than about 0.75 µm.

[0011] Thus, in a further aspect of the present invention, there is provided an inorganic particulate material having a d98 of less than about 11 µm, or less than about 8 µm, and comprising equal to or less than about of 40% by weight of particles smaller than about 0.75 µm.

[0012] In certain embodiments, the inorganic particulate material did not withstand dry sieving or screening. Thus, in a further aspect of the present invention, there is provided an inorganic particulate material having a d98 of less than about 11 µm, or equal to or less than about 8 µm, in which the inorganic particulate material did not withstand a dry sieving or screening.

[0013] In certain embodiments, the inorganic particulate material comprises equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 25 µm. Thus, in a further aspect of the present invention, there is provided an inorganic particulate material having a d98 of less than about 11 µm, or equal to or less than about 8 µm, and comprising equal to or more than about of 3 ppm particles having a particle size equal to or greater than about 3 ppm.

[0014] According to a second aspect of the present invention, there is provided a composition comprising an inorganic particulate material according to any aspect or embodiment of the present invention.

[0015] According to a third aspect of the present invention, there is provided a composition comprising a polymer and an inorganic particulate material according to any aspect or embodiment of the present invention. In certain embodiments, the composition can be a polymeric film (e.g., lamination coating, such as LDPE lamination coating), or synthetic paper, or raffia.

[0016] According to a fourth aspect of the present invention, there is provided a polymeric film comprising a polymer and an inorganic particulate material according to any aspect or embodiment of the present invention.

[0017] According to a fifth aspect of the present invention, there is provided a use of an inorganic particulate material according to any aspect or embodiment of the present invention in a polymer composition, such as a polymeric film (e.g., lamination coating , such as LDPE lamination coating), synthetic paper, or raffia.

[0018] According to a sixth aspect of the present invention, there is provided a method for producing a polymeric film, the method comprising: mixing (e.g. compounding) a polymer and an inorganic particulate material according to any aspect or embodiment of the present invention; and casting the composite material into a film.

[0019] According to a seventh aspect of the present invention, there is provided a use of an inorganic particulate material according to any aspect or embodiment of the present invention as a cavitation agent.

[0020] According to an eighth aspect of the present invention, there is provided a use of an inorganic particulate material according to any aspect or embodiment of the present invention in a polymeric film to reduce the release of inorganic particulate material from the polymeric film, and/or reduce the deposition of inorganic particulate matter on the surface of the polymeric film (sweeping). This can, for example, be compared to a polymeric film which is identical except that it does not comprise the inorganic particulate material according to any aspect or embodiment of the present invention.

[0021] In certain embodiments of any aspect of the present invention, the inorganic particulate material comprises equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 25 µm.

[0022] In certain embodiments of any aspect of the present invention, the inorganic particulate material comprises equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 40 µm.

[0023] In certain embodiments of any aspect of the present invention, the inorganic particulate material comprises equal to or less than about 40% by weight of particles smaller than about 0.75 µm.

[0024] In certain embodiments of any aspect of the present invention, the inorganic particulate material has a d98 equal to or less than about 11 µm, or equal to or less than about 8 µm.

[0025] In certain embodiments of any aspect of the present invention, the inorganic particulate material does not withstand dry sieving or screening.

[0026] In certain embodiments of any aspect of the present invention, the inorganic particulate material is an alkaline earth metal carbonate, such as calcium carbonate. In certain embodiments of any aspect of the present invention, the inorganic particulate material has a d50 ranging from about 0.5 µm to about 3 µm. In certain embodiments of any aspect of the present invention, the inorganic particulate material has a d50 ranging from about 0.5 µm to about 2.5 µm.

[0027] In certain embodiments of any aspect of the present invention, the polymer composition is a polymeric film (e.g., lamination coating, such as LDPE lamination coating). In certain embodiments of any aspect of the present invention, the polymeric film is breathable.

[0028] Certain embodiments of the present invention can provide one or more of the following advantages: reduce the average particle size of the particulate material; reduce the % of ultrafine particles (particles smaller than 0.75 μm) in the inorganic particulate material; reduce d98 top cut of inorganic particulate matter; increase the slope of the particle size distribution; increase the % of very coarse particles (eg larger than 20 μm); reduce or eliminate inorganic particle sieving prior to incorporation into polymeric films; maintain or improve the dispersion of inorganic particulate matter; maintain or reduce the moisture uptake of the inorganic particulate material; decrease the thickness (production of thinner films); maintain or increase the breathability (eg MVTR) of the film; maintain film strength and flexibility; lowering the level of "volatile" components in the film and high processing temperatures; improve the processing of polymeric compositions (eg, masterbatches or polymeric fibers or films (eg, by reducing operating time)); allow for faster line speeds in the production of the inorganic particulate material and/or the polymeric films; retention of inorganic particulate matter in polymeric films (i.e., "scavenging" reduction); improved cavitation agent for breathable films.

[0029] The details, examples and preferences provided herein in relation to any particular one or more of the cited aspects of the present invention apply equally to all aspects of the present invention. Any combination of the embodiments, examples and preferences described herein in all possible variations thereof is encompassed by the present invention, unless otherwise indicated, or otherwise clearly contradicted by the context.

DETAILED DESCRIPTION OF THE INVENTION Inorganic Particulate Material

[0030] An inorganic particulate material suitable for use in polymeric compositions, such as polymeric films, is described herein. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 25 µm. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 40 µm. In certain embodiments, the inorganic particulate material does not support dry screening or screening. Inorganic particulate matter can have a d98 of less than about 11 µm, or less than about 8 µm. Inorganic particulate materials having these particle size properties have advantageously found themselves suitable for use in polymer compositions, such as polymeric films. In particular, these inorganic particulate materials have been useful in reducing the thickness of polymeric films without causing processing problems such as increased operating time for forming the films. In particular, these inorganic particulate materials have been useful in reducing the viscosity of polymer melts, for example, at high loading concentrations (eg, greater than 50% by weight). Surprisingly, it has been found that these advantageous properties are maintained when the inorganic particulate material includes some very coarse particles (e.g., particles equal to or greater than about 25 µm, or equal to or greater than about 40 µm).

[0031] The inorganic particulate material may comprise equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 25 µm. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 5 ppm of particles having a particle size equal to or greater than about 25 µm, for example, equal to or greater than about 10 ppm , for example, equal to or greater than about 20 ppm, for example, equal to or greater than about 50 ppm of particles having a particle size equal to or greater than about 25 µm. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 0.01% by weight of particles having a particle size equal to or greater than about 25 µm, for example, equal to or greater than about 0.02% by weight, for example, equal to or greater than about 0.03% by weight, for example, equal to or greater than about 0.04% by weight, for example, equal to or greater than about 0.05% by weight of particles having a particle size equal to or greater than about 25 µm.

[0032] In certain embodiments, the inorganic particulate material comprises up to about 1.5% by weight of particles having a particle size equal to or greater than about 25 µm. In certain embodiments, the inorganic particulate material comprises up to about 1% by weight, for example, up to about 0.9% by weight, for example, up to about 0.8% by weight, for example, up to about 0. .7% by weight, for example, to about 0.6% by weight, for example, to about 0.5% by weight, for example, to about 0.4% by weight of particles having a size of particle equal to or larger than about 25 µm.

[0033] The inorganic particulate material may comprise equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 40 µm. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 5 ppm of particles having a particle size equal to or greater than about 40 µm, for example, equal to or greater than about 10 ppm , for example, equal to or greater than about 20 ppm, for example, equal to or greater than about 50 ppm of particles having a particle size equal to or greater than about 40 µm. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 0.01% by weight of particles having a particle size equal to or greater than about 40 µm, for example, equal to or greater than about 0.02% by weight, for example, equal to or greater than about 0.03% by weight, for example, equal to or greater than about 0.04% by weight, for example, equal to or greater than about 0.05% by weight of particles having a particle size equal to or greater than about 40 µm.

[0034] In certain embodiments, the inorganic particulate material comprises up to about 1.5% by weight of particles having a particle size equal to or greater than about 40 µm. In certain embodiments, the inorganic particulate material comprises up to about 1% by weight, for example, up to about 0.9% by weight, for example, up to about 0.8% by weight, for example, up to about 0. .7% by weight, for example, to about 0.6% by weight, for example, to about 0.5% by weight, for example, to about 0.4% by weight of particles having a size of particle equal to or larger than about 40 µm.

[0035] The inorganic particulate material may comprise equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 38 µm, or about 30 µm, or about 25 µm, or about 20 µm. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 5 ppm of particles having a particle size equal to or greater than about 38 µm, or about 30 µm, or about 25 µm, or about 20 µm, for example, equal to or greater than about 10 ppm, for example, equal to or greater than about 20 ppm, for example, equal to or greater than about 50 ppm of particles having a particle size equal to or greater than about 38 µm, or about 30 µm, or about 25 µm, or about 20 µm. In certain embodiments, the inorganic particulate material comprises equal to or greater than about 0.01% by weight of particles having a particle size equal to or greater than about 38 µm, or about 30 µm, or about 25 µm, or about 20 µm, for example, equal to or greater than about 0.02% by weight, for example, equal to or greater than about 0.03% by weight, for example, equal to or greater than about 0.04% by weight, for example, equal to or greater than about 0.05% by weight of particles having a particle size equal to or greater than about 38 µm, or about of 30 μm, or about 25 μm, or about 20 μm.

[0036] In certain embodiments, the inorganic particulate material comprises up to about 2% by weight of particles having a particle size equal to or greater than about 38 µm, or about 30 µm, or about 25 µm, or about 20 µm. In certain embodiments, the inorganic particulate material comprises up to about 1% by weight, for example, up to about 0.9% by weight, for example, up to about 0.8% by weight, for example, up to about 0. .7% by weight, for example, to about 0.6% by weight, for example, to about 0.5% by weight, for example, to about 0.4% by weight of particles having a size of particle equal to or larger than about 38 µm, or about 30 µm, or about 25 µm, or about 20 µm.

[0037] The inorganic particulate matter may have a d98 (top cut) of less than about 11 μm. In certain embodiments, the inorganic particulate material has a d98 equal to or less than about 10 µm, e.g., less than about 9 µm, e.g., less than about 8 µm, e.g., less than about about 7.5 μm, for example, equal to or less than about 7 μm, for example, equal to or less than about 6.5 μm, for example, equal to or less than about 6 μm , for example, equal to or less than about 5.5. μm, for example, equal to or less than about 5 μm. In certain embodiments, the inorganic particulate matter has a d98 ranging from about 3 µm to about 11 µm, or from about 3 µm to about 10 µm, or from about 3 µm to about 9 µm, or from about from about 3 µm to about 8 µm, for example from about 3.5 µm to about 7 µm, for example from about 4 µm to about 6 µm, for example from about 4.5 µm to about 5.5 μm, for example about 5 μm.

[0038] Inorganic particulate matter may, for example, have a d50 ranging from about 0.5 μm to about 3 μm, for example, from about 0.5 μm to about 2.75 μm, for example, from about 0.5 µm to about 2.5 µm, for example, from about 0.75 µm to about 2.2 µm, for example, from about 0.8 µm to about 2 µm. In certain embodiments, the inorganic particulate material has a d50 ranging from about 0.5 µm to about 1.5 µm, for example, from about 0.6 µm to about 1.4 µm, for example, from about from about 0.7 µm to about 1.3 µm, for example, from about 0.75 µm to about 1.25 µm, for example, from about 0.8 µm to about 1.2 µm, for example for example, from about 0.9 µm to about 1.1 µm, for example about 1 µm. In certain embodiments, the inorganic particulate material has a d50 ranging from about 1 µm to about 2.5 µm, for example, from about 1.5 µm to about 2.5 µm, for example, from about 1 .5 µm to about 2 µm, for example from about 1.7 µm to about 2 µm.

[0039] The % of inorganic particulate matter particles smaller than 0.75 μm may, for example, be equal to or less than about 40% by weight, for example, equal to or less than about 39% by weight, for example, equal to or less than about 38% by weight, for example, equal to or less than about 37% by weight, for example, equal to or less than about 36% by weight , for example, equal to or less than about 35% by weight. In certain embodiments, the % inorganic particulate matter particles less than 0.75 µm is equal to or less than about 25% by weight, for example, equal to or less than about 24% by weight, by for example, equal to or less than about 23% by weight, for example, equal to or less than about 22% by weight, for example, equal to or less than about 21% by weight, for example, equal to or less than about 20% by weight. In certain embodiments, the % of particles smaller than 0.75 µm can be equal to or greater than about 1% by weight, for example, equal to or greater than about 2% by weight, for example, equal to at or greater than about 5% by weight.

[0040] The % of inorganic particulate matter particles smaller than 0.5 μm may, for example, be equal to or less than about 25% by weight, for example, equal to or less than about 24% by weight, for example, equal to or less than about 23% by weight, for example, equal to or less than about 22% by weight, for example, equal to or less than about 21% by weight , for example, equal to or less than about 20% by weight. In certain embodiments, the % inorganic particulate matter particles smaller than 0.5 µm is equal to or less than about 15% by weight, for example, equal to or less than about 14% by weight, by for example, equal to or less than about 13% by weight, for example, equal to or less than about 12% by weight. In certain embodiments, the % of particles smaller than 0.5 µm can be equal to or greater than about 1% by weight, for example, equal to or greater than about 2% by weight, for example, equal to at or greater than about 5% by weight.

[0041] The % of inorganic particulate matter particles smaller than 5 μm can, for example, range from about 85% by weight to about 99% by weight, for example, from about 90% by weight to about 99% by weight. In certain embodiments, the % of particles smaller than about 5 µm can range from about 85% by weight to about 95% by weight, for example, from about 90% by weight to about 95% by weight. In certain embodiments, the % of particles smaller than about 5 µm can range from about 90% by weight to about 99% by weight, for example, from about 95% by weight to about 99% by weight.

[0042] The % of inorganic particulate matter particles smaller than 2 µm can, for example, range from about 40% by weight to about 95% by weight, for example, from about 45% by weight to about 90% by weight, for example, from about 50% by weight to about 90% by weight. In certain embodiments, the % of particles smaller than 2 µm can range from about 40% by weight to about 70% by weight, for example, from about 45% by weight to about 65% by weight, for example , from about 50% by weight to about 60% by weight. In certain embodiments, the % of particles smaller than 2 µm can range from about 70% by weight to about 95% by weight, for example, from about 75% by weight to about 90% by weight, for example , from about 80% by weight to about 90% by weight.

[0043] The % of inorganic particulate matter particles smaller than 1 µm can, for example, range from about 15% by weight to about 65% by weight, for example, from about 20% by weight to about 60% by weight, for example, from about 25% by weight to about 55% by weight. In certain embodiments, the % of particles smaller than 1 µm can range from about 15% by weight to about 40% by weight, for example, from about 15% by weight to about 35% by weight, for example from about 20% by weight to about 35% by weight, for example from about 20% by weight to about 30% by weight. In certain embodiments, the % of particles smaller than 1 µm can range from about 30% by weight to about 60% by weight, for example, from about 40% by weight to about 60% by weight, for example , from about 45% by weight to about 55% by weight.

[0044] The inorganic particulate material can, for example, have a slope factor of at least about 35. For example, the inorganic particulate material can have a slope factor ranging from about 35 to about 55, for example, from about 40 to about 50, for example, from about 41 to about 49, for example, from about 42 to about 48, for example, from about 43 to about 47, for example, from about from 44 to about 46, for example about 45. Slope factor is defined as (d30/d70) x 100.

[0045] In certain embodiments, the inorganic particulate matter has a d98 of less than about 8 μm, a d50 ranging from about 0.5 μm to about 1.5 μm, a % of particles less than 5 μm ranging from about 90% by weight to about 99% by weight, a % of particles smaller than 2 µm ranging from about 75% by weight to about 95% by weight, and a % of particles of less than 1 µm ranging from about 40% by weight to about 60% by weight.

[0046] In certain embodiments, the inorganic particulate matter has a d98 of less than about 6 μm, a d50 ranging from about 0.75 μm to about 1.25 μm, a % of particles less than 5 μm ranging from about 95% by weight to about 99% by weight, a % of particles smaller than 2 µm ranging from about 80% by weight to about 90% by weight, and a % of particles of less than 1 µm ranging from about 44% by weight to about 55% by weight.

[0047] In certain embodiments, the inorganic particulate material has a d98 of less than about 5 μm, a d50 of about 1 μm, a % particulate matter of less than 5 μm ranging from about 96% by weight to about of 99% by weight, a % of particles smaller than 2 µm ranging from about 82% by weight to about 88% by weight, and a % of particles smaller than 1 µm ranging from about 47% by weight to about 53% by weight.

[0048] In certain embodiments, the inorganic particulate matter has a d98 of less than about 8 μm, a d50 ranging from about 1 μm to about 2.5 μm, a % of particles less than 5 μm ranging from about 90% by weight to about 99% by weight, a % of particles smaller than 2 µm ranging from about 45% by weight to about 65% by weight, and a % of particles smaller than 1 µm ranging from about 20% by weight to about 35% by weight.

[0049] In certain embodiments, the inorganic particulate matter has a d98 of less than about 7 μm, a d50 ranging from about 1.5 μm to about 2 μm, a % of particles less than 5 μm ranging from about 90% by weight to about 97% by weight, a % of particles smaller than 2 µm ranging from about 50% by weight to about 60% by weight, and a % of particles smaller than 1 µm ranging from about 22% by weight to about 32% by weight.

[0050] In certain embodiments, the inorganic particulate matter has a d98 of less than about 7 μm, a d50 ranging from about 1.7 to about 1.9 μm, a % of particles less than 5 μm ranging from about 92% by weight to about 97% by weight, a % of particles smaller than 2 µm ranging from about 52% by weight to about 58% by weight, and a % of particles smaller than 1 µm ranging from about 24% by weight to about 30% by weight.

[0051] The % of particles smaller than 0.25 μm may, for example, be equal to or less than about 10% by weight, for example, equal to or less than about 9% by weight, for for example, equal to or less than about 8% by weight, for example, equal to or less than about 7% by weight, for example, equal to or less than about 6% by weight, for example, equal to or less than about 4% by weight. The % of particles smaller than 0.25 µm can, for example, be at least about 1% by weight.

[0052] The % of particles smaller than 0.1 μm may, for example, be equal to or less than about 5% by weight, for example, equal to or less than about 4% by weight, for for example, equal to or less than about 3% by weight, for example, equal to or less than about 2% by weight. The % of particles smaller than 0.1 µm can, for example, be at least about 0.1% by weight.

[0053] Unless otherwise noted, the particle size properties referred to herein for the inorganic particulate materials are as measured in a well known manner by settling the particulate filler or material in a fully dispersed condition in an aqueous medium using a Sedigraph 5100 machine as supplied by Micromeritics Instruments Corporation, Norcross, Georgia, USA (phone: +17706623620; website: www.micromeritics.com), referred to herein as a "Micromeritics Sedigraph 5100 unit". Such a machine provides measurements and a trace of the cumulative percentage by weight of particles having a size, referred to in the art as 'equivalent spherical diameter' (e.s.d), smaller than given e.s.d values. The d50 mean particle size is the thus determined value of the e.s.d of the particle in which there are 50% by weight of the particles having an equivalent spherical diameter less than the d50 value. The d98 and d90 are the values thus determined from the e.s.d. of the particle in which there are 98% and 90% respectively by weight of the particles having an equivalent spherical diameter less than the d98 value or d90 value. Unless otherwise noted, particle size properties referred to herein refer to the particle size properties of inorganic particulate materials prior to any surface treatment (i.e., no coating).

[0054] The desired particle size distribution can, for example, be obtained by any suitable method known to the person skilled in the art. For example, the desired particle size distribution can be obtained using one or more of the following methods, dry sieving or screening, removal of fine particles before they become "over land" (e.g. using hydrocyclone), removal of fine particles of dried products by air classification, Ostwald ripening process.

[0055] The inorganic particulate material may, for example, be alkaline earth metal carbonate, (for example, dolomite, i.e., CaMg(CO3)2, or calcium carbonate), metal sulfate, (for example, barite or gypsum), metal silicate, metal oxide (e.g. titania, iron oxide, chromia, antimony trioxide, or silica), metal hydroxide (e.g. alumina trihydrate), kaolin, calcined kaolin, wollastonite, bauxite , talc or mica, including combinations thereof. For example, the inorganic particulate material can be an alkaline earth metal carbonate, such as calcium carbonate. Next, the present invention may tend to be discussed in terms of calcium carbonate. However, the invention should not be construed as being limited to calcium carbonate.

[0056] The particulate calcium carbonate in the present invention can be obtained from a natural source by grinding, or it can be prepared synthetically by precipitation (PCC), or it can be a combination of the two, that is, a mixture of the naturally derived ground material , and the precipitated synthetic material. PCC can also be crushed.

[0057] Crushed calcium carbonate (GCC), i.e. natural crushed calcium carbonate is typically obtained by grinding a mineral source such as chalk, marble or limestone, which may be followed by a particle size grading step , so as to obtain a product having the desired degree of fineness. The particulate solid material may be comminuted autogenously, i.e., by attrition between the solid material particles, or alternatively, in the presence of a particulate comminution medium comprising particles of a different material from the calcium carbonate to be comminuted.

[0058] Wet grinding of calcium carbonate involves forming an aqueous suspension of the calcium carbonate which can then be ground, optionally in the presence of a suitable dispersing agent. Reference may be made to, for example, EP-A-614948 (the contents of which are incorporated by reference in their entirety) for further information relating to wet grinding of calcium carbonate.

[0059] When filler is obtained from naturally occurring sources, it may be that some mineral impurities will inevitably contaminate the crushed material. For example, naturally occurring calcium carbonate occurs in association with other minerals. Also, in some circumstances, minor additions of other minerals may be included, for example one or more of kaolin, calcined kaolin, wollastonite, bauxite, talc or mica, may also be present. In general, however, the filler used in the invention will contain less than 5% by weight, preferably less than 1% by weight of other mineral impurities.

[0060] PCC can be used as the source of particulate calcium carbonate in the present invention, and can be produced by any of the known methods available in the art. TAPPI Monograph Series No 30, "Paper Coating Pigments", pages 34-35, describes the three main commercial processes for preparing precipitated calcium carbonate that is suitable for use in preparing products for use in the paper industry, but can also be used in practicing the present invention. In all three processes, limestone is first calcined to produce quicklime, and the quicklime is then quenched in water to produce calcium hydroxide or milk of lime. In the first process, the milk of lime is directly carbonated with carbon dioxide gas. This process has the advantage that no byproducts are formed, and it is relatively easy to control the properties and purity of the calcium carbonate product. In the second process, milk of lime is contacted with soda ash to produce, by double decomposition, a calcium carbonate precipitate and a sodium hydroxide solution. Sodium hydroxide must be substantially completely separated from calcium carbonate if this process is to be commercially attractive. In the third main commercial process, milk of lime is first contacted with ammonium chloride to give a solution of calcium chloride and ammonia gas. The calcium chloride solution is then contacted with soda ash to produce, by double decomposition, precipitated calcium carbonate and a sodium chloride solution.

[0061] The process for producing PCC results in very pure calcium carbonate crystals and water. Crystals can be produced in a variety of different shapes and sizes, depending on the specific reaction process that is used. The three main forms of PCC crystals are aragonite, rhombohedral and scalenohedral, all of which are suitable for use in the present invention, including mixtures thereof.

[0062] Optionally, the inorganic particulate material can be treated on the surface (coated). For example, inorganic particulate material (eg, calcium carbonate (GCC or PCC)) can be coated with a hydrofibizing surface treatment agent, such as an aliphatic compound. For example, calcium carbonate can be coated with one or more aliphatic carboxylic acids, or salts thereof, having at least 10 carbon atoms in the chain. For example, calcium carbonate can be coated with one or more fatty acids or salts or esters thereof. The fatty acids can be selected from stearic acid, palmitic acid, behenic acid, montanic acid, capric acid, lauric acid, myristic acid, isostearic acid and cerotic acid. The coated/surface treated calcium carbonate may be a stearate coated calcium carbonate (eg ammonium stearate coated calcium carbonate). The inventors of the present invention have found that stearate-coated calcium carbonate is particularly effective, even more particularly stearate-coated GCC.

[0063] In certain embodiments, the level of coating is such that the inorganic particulate material is substantially in monolayer form. This could, for example, mean that there is a slight overcoating. This can, for example, be advantageous where the additional coating provides additional lubrication of the finer particles, and there can be, for example, low levels of volatiles at high temperatures during processing of polymeric films. The level of coating can be about 0.5% by weight to about 1.5% by weight, for example, about 0.8% by weight to about 1.3% by weight based on the dry weight of the filler. particulate.

[0064] Other suitable coated or treated fillers include calcined treated kaolin and treated talc. Calcined kaolin can, for example, be treated with a silane (for example an organosilane) or propylene glycol, whereas talc can be treated with a silane (for example an organosilane).

[0065] The filler can be dried before inclusion in a composition. For example, the filler can be dried before blending with a polymer resin. Typically, the charge can be dried in a conventional oven at about 80°C. The polymer can be dried in a vacuum oven at approximately 80°C. The particulate filler may be dried to such an extent that the particulate filler has and maintains an adsorbed water (or moisture) content of no greater than about 0.5% by weight, for example, and particularly advantageously, no greater than about 0.2% by weight, or not greater than about 0.1% by weight, based on the dry weight of the particulate filler. This includes both uncoated and coated particulate fillers. Low levels of adsorbed water are particularly beneficial when filler is used to form breathable films.

[0066] Desirably, particulate cargo, including when either coated or uncoated, is not susceptible to substantial additional moisture pick-up. The particulate filler may, for example, have a moisture level of not more than about 0.5% by weight, for example not greater than about 0.2% by weight, for example not greater than about 0.1% by weight after exposure to an atmosphere of 97% or greater relative humidity for 48 hours at a temperature of 20°C.

[0067] The particulate filler may be free or substantially free of hygroscopic or hydrophilic compounds. For example, during comminution of the particulate feedstock, comminution can be carried out in the absence of added hygroscopic or hydrophilic compounds, or if wet comminution, any dispersants employed can be minimized and/or subsequently removed from the feedstock in a known manner. For example, no more than about 0.05% by weight of the hydrophilic component can be present in the particulate filler based on the dry weight of the particulate filler. For example, no more than about 0.05% by weight of a dispersant, for example a hydrophilic dispersant, can be present in the particulate feed based on the dry weight of the particulate feed. An example of such a dispersant is sodium polyacrylate. The moisture level can be measured in a known manner, for example by a Karl Fischer (KF) grinding apparatus. In this method, water can be removed from the sample by heating, and then measured using the quantitative reaction of water with iodine. In colorimetric KF titration, the sample is added to a pyridine-methanol solution (with iodine and sulfur dioxide as major components). The electrolytically generated iodine in the anode reacts with water. The amount of water can be directly determined from the amount of electrical charge required for electrolysis.

Compositions Comprising Inorganic Particulate Material

[0068] Compositions comprising the inorganic particulate material described herein (including all embodiments and combinations thereof), are also described. The compositions may, for example, be an aqueous slurry. The compositions may, for example, be polymer compositions comprising a polymer and the inorganic particulate material. The polymer compositions can, for example, be a polymeric film, a polymer fiber, a woven or non-woven material, a synthetic paper (paper produced partially or completely from synthetic polymer, for example, having the properties of traditional paper, such as such as folding and printing, but do not tear, puncture or absorb water as easily), or raffia (e.g. in raffia ribbon or woven raffia packaging) (e.g. polypropylene raffia). In certain embodiments, the inorganic particulate material is incorporated into a polymer film. In certain embodiments, the inorganic particulate material is incorporated into a lamination coating, for example, a polyethylene lamination coating (e.g., low density polyethylene (LDPE) lamination coating). Advantageously, the inorganic particulate material is incorporated into a breathable polymer film.

[0069] The polymer film comprises a polymer and an inorganic particulate material. The polymer can be a homopolymer or a copolymer. Suitable polymers include thermoplastic resins, such as polyolefin resin, for example, including monoolefin ethylene polymers, propylene, butene, or the like, functionalized derivatives, and physical mixtures and copolymers thereof. Typical examples of the polyolefin resin include polyethylene resins such as low density polyethylene, linear low density polyethylene (ethylene-α-olefin copolymer), medium density polyethylene, and high density polyethylene; polypropylene resins, such as polypropylene and ethylene-polypropylene copolymer; poly(4-methylpentene); polybutene; ethylene vinyl acetate copolymer; polyvinyl chloride; polyethylene terephthalate; and mixtures thereof. These polyolefin resins can be obtained by polymerization in a known manner, for example by using a Ziegler catalyst, or obtained by using a single site catalyst such as a metallocene catalyst. In certain embodiments, the polymer film is biaxially oriented polypropylene (BOPP), or biaxially oriented polyethylene terephthalate (BOPET).

[0070] Before use, the polymer may be dried until a required level of dryness is achieved. The inorganic particulate material can also be independently dried before mixing with the polymer.

[0071] Optionally, the polymer composition (e.g. polymer film) may further comprise one or more additives. Examples of useful additives include, but are not limited to, opacifying agents, pigments, colorants, glidants, antioxidants, anti-fog agents, anti-static agents, anti-blocking agents, moisture barrier additives, barrier additives gas, hydrocarbon resins, or hydrocarbon waxes. In certain embodiments, the polymer film additionally comprises a binding agent, or tackifying agent.

[0072] Optionally, the polymer composition (e.g. polymer film) may additionally comprise one or more additional inorganic particulate materials (not according to the inorganic particulate materials of the invention). Additional fillers can, for example, be calcium carbonate, barium sulfate, calcium sulfate, barium carbonate, magnesium hydroxide, aluminum hydroxide, zinc oxide, magnesium oxide, titanium oxide, silica, talc, kaolin, and combinations thereof.

[0073] Inorganic particulate matter, which may or may not have been surface treated, can be incorporated into polymer compositions, and is typically present at a concentration of about 1% by weight to about 80% by weight, per for example from about 1% by weight to about 60% by weight, for example from about 2 to 55% by weight by weight of the final polymer film. For example, inorganic particulate material can be incorporated into polymer compositions at a concentration of about 5 to 50% by weight, for example about 10 to 25% by weight. For use in breathable films, inorganic particulate matter, which may or may not have been surface treated, can be incorporated into polymer compositions, and is typically present at a concentration of about 30% by weight to about 55% by weight. weight for weight of the final polymer film, for example, about 45% by weight to about 55% by weight.

[0074] The polymer that can be incorporated into the composition is typically present at a concentration of about 45% to about 98% by weight of the final polymer composition (e.g., polymer film). For example, the polymer is typically present at a concentration of from about 50% to about 95%, for example, about 50% to about 90%, for example, about 55% to about 90%, for example , about 60% to about 85%, for example, about 65% to about 80%, by weight of the final polymer composition (e.g., polymer film).

[0075] A film is a sheet or layer or material having an average thickness of up to 250 µm. The polymer film can, for example, have a thickness ranging from about 5 µm to about 250 µm. For example, the polymer film can have a thickness ranging from about 5 µm to about 50 µm, for example from about 5 µm to about 20 µm, for example from about 5 µm to about 15 µm , for example, from about 5 µm to about 10 µm.

[0076] The polymer film may, for example, be a breathable polymer film which allows transmission of gases and vapors. The polymer film can, for example, have a moisture vapor transmission rate (MVTR) ranging from about 2000 gsm/day to about 15,000 gsm/day, as calculated in accordance with ASTM E96/E96M-05. For example, the polymer film can have an MVTR of at least about 3000 gsm/day, for example, at least about 4000 gsm/day, for example, at least about 5000 gsm/day, for example, at least about 6000 gsm/day. For example, the polymer film can have an MVTR ranging from about 5000 to about 15,000 gsm/day, for example, from about 8000 to about 15,000 gsm/day, for example, from about 10,000 to about 15,000 gsm/day, for example, from about 11,000 to about 14,000 gsm/day, for example, from about 11,000 to about 13,000 gsm/day, for example, from about 11,000 to about 12,000 gsm/day.

[0077] The inorganic particulate material described herein can be used in a polymeric film in order to reduce the release of inorganic particulate material from the polymeric film, and/or reduce the deposition of inorganic particulate material on the surface of the polymeric film (sweeping) . The reduction can, for example, be compared to polymeric film which is identical except that it does not comprise an inorganic particulate material according to any aspect or embodiment of the invention.

Composition Production Methods

[0078] Methods of producing polymer compositions (eg polymer films) described herein are also described. The polymer (resin) can be melted (or otherwise softened) prior to forming the polymer composition (e.g., film), and the polymer will normally not be subjected to any further chemical transformations. After formation of the polymer composition (eg, film), the polymer resin can be cooled and allowed to set.

[0079] The polymer composition can be produced by methods that are well known in the art generally in which a particulate filler and a polymer are mixed together in suitable proportions to form a mixture (so-called "composition"). The polymer may be in a liquid form to enable the filler particles to be dispersed therein. Where polymers are solid at ambient temperatures, the polymer resin may need to be melted before compounding can be effected. In some embodiments, the particulate filler can be dry blended with polymer particles, dispersion of the particles in the resin then being effected when the melt is obtained prior to forming a film from the melt, for example in a proper extruder.

[0080] In the embodiments of the invention, the polymer and particulate filler and, if necessary, any other optional additives, can be formed into a suitable masterbatch by using a suitable compounder/mixer in a manner known per se, and can be pelletized , for example, by the use of a single screw extruder, or a twin screw extruder, which form braids that can be cut or broken into pellets. The composer may have a single intake for introducing the filler and polymer resin together. Alternatively, separate inlets can be provided for the filler and polymer resin. Suitable composers are commercially available, for example from Coperion (early Werner & Pfleiderer).

[0081] The polymer compositions according to the present invention can be processed to form, or to be incorporated into, polymer films in any suitable manner. Methods of producing polymer films (e.g., laminating coatings) are well known to those skilled in the art, and can be prepared in a conventional manner. Known methods include the use of casting, extrusion, and blow molding processes. For example, blown film extrusion lines can be used. For those examples where polymer blends are used, then co-extrusion techniques can be used. Co-extrusion methods are well known to the person skilled in the art. Typically, two or more streams of molten polymer resin are joined into a single extrudate stream in such a way that the resins bond together but do not mix. Generally, a separate extruder is required for each stream, and the extruders are linked so that the extrudates can flow together in a manner appropriate for the desired application. To produce layered films, several extruders can be used in combination, and fed together into a complex die that mixes each of the resin streams into a layered film, or interlayer material.

[0082] The use of fillers in breathable films is described in WO 99/61521, US6569527 B1 and WO 2013/061068, the contents of which are hereby incorporated in their entirety by reference.

[0083] In the manufacture of a breathable film, a blend or masterbatch of the polymer (eg thermoplastic polyolefin resin) and the filler may first be produced by mixing and compounding prior to the film production stages. The mixture of ingredients to be blended per compounding may include, in addition to the resin and particulate filler, other known optional ingredients employed in thermoplastic films, for example, one or more of binding agents or tackifying agents, plasticizers, lubricants, antioxidants, ultraviolet absorbers, dyes, colorants. A bonding agent or tackifying agent where employed can facilitate bonding of the film after formation to another member, for example, a fibrous nonwoven layer, or one or more nonporous layers.

[0084] The polymer, filler, and, if necessary, other additional additives, can be mixed by using a suitable mixer/mixer, for example, a Henschel mixer, a super mixer, a drum type mixer, or the like, and kneaded, and can be pelletized, for example, by using a single screw extruder, or a twin screw extruder, which forms braids that can be cut or broken into pellets. The masterbatch or blend, for example in the form of pellets, can be melted and formed into a film by use of a known film-forming and molding machine.

[0085] The film may be a blown film, cast film, or extruded film. The film as initially formed may generally be too thick and too noisy as it tends to produce a vibrating noise when shaken, and the film may not yet have a sufficient degree of breathability as measured by its water vapor transmission rate. . Accordingly, the film can be heated, for example, to a temperature of about 5°C less than the melting point of the thermoplastic polymer, or more, and then stretched to at least about 1.2 times, for example, at least about 2.5 times its original length to thin the film and make it porous.

[0086] An additional characteristic of the thinning process is the change in the opacity of the film. As formed, the film is relatively transparent, but upon stretching, it becomes opaque. In addition, while the film becomes oriented during the stretching process, it also becomes softer and does not have the degree of wobble that it had prior to stretching. Taking all these factors into account, and the desire to have a water vapor transmission rate of, for example, at least 100 grams per square meter per 24 hours, the film can, for example, be thinned to such an extent that it has a unit area weight of less than about 35 grams per square meter for absorbent personal care article applications, and a unit area weight of less than about 18 grams per square meter for certain other applications.

[0087] The molding and film-forming machine may, for example, comprise an extruder equipped with a T-mold or the like, or an inflation molding machine equipped with a circular mould. Film production can be carried out some time after masterbatch production, possibly in a different production facility. In some cases, the masterbatch can be formed directly onto the skin without producing an intermediate product, for example by pelletizing.

[0088] The film may be stretched in at least one uniaxial direction at a temperature from room temperature to the softening point of the resin in a manner known as a roller method or a tension method to provide interfacial separation of the resin and the particulate load together, whereby a porous film can be prepared. Stretching can be carried out in one step or in several steps. Stretch magnification determines film tearing at high stretch as well as breathability and moisture vapor transmission of the obtained film, and thus excessively high stretch magnification and excessively low stretch magnification are desirably avoided. The stretch magnification is preferably in the range of about 1.2 to 5 times, for example about 1.2 to 4 times, in at least one uniaxial direction. If biaxial stretching is performed, it is possible that, for example, stretching in a first direction is applied in the machine direction, or a direction perpendicular to it, and stretching in a second direction is then applied at right angles to the first direction. Alternatively, biaxial stretching can be performed simultaneously in the machine direction and perpendicular to the machine.

[0089] After stretching, a heat setting treatment can be carried out if required in order to stabilize the shape of voids obtained. The heat setting treatment may be, for example, a heat setting treatment at a temperature in the range of the softening point of the resin to a temperature lower than the melting point of the resin for a period of about 0, 1 to about 100 seconds. The thickness should preferably be such as to obtain a film that is unlikely to tear or break, and that has appropriate softness and good feel.

Uses of Compositions

[0090] The porous or breathable film prepared according to the present invention can have adequate breathability, moisture vapor transmission and feel, as well as excellent mechanical properties and long-term adhesive properties. The breathable film can, for example, suitably be used in products such as disposable diapers, body fluid absorbing pads and bed sheets; medical materials such as surgical supplies and base materials for hot packs; clothing materials such as sweaters, rainwear; building materials such as wallpapers and waterproof materials for roofs and house sheds; packaging materials for packaging desiccants, dehumidifying agents, deoxidizers, insecticides, disposable body warmers; packaging materials for maintaining the freshness of various articles and foods; cell separators; and the like. The breathable film is particularly desirable as a material used in products such as disposable diapers and body fluid absorbing pads. The breathable film may, in such products, be formed into a composite or laminate with one or more other layers, for example a fibrous non-woven layer, for example by an adhesive or bonding agent.

[0091] For the avoidance of doubt, the present invention may be as defined in any of the following numbered paragraphs:

[0092] 1. An inorganic particulate material comprising: (a) equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 40 μm, and having a d98 less than about of 11 µm; or (b) equal to or greater than about 3 ppm of particles having a particle size equal to or greater than about 40 µm, and equal to or less than about 40% by weight of particles less than about 0.75 µm; or (c) equal to or less than about 40% by weight of particles smaller than about 0.75 µm, and having a d98 of less than about 11 µm.

[0093] 2. The inorganic particulate matter according to paragraph 1, comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 25 μm.

[0094] 3. The inorganic particulate matter according to paragraph 1 or 2, comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 38 μm, or equal to or greater than about 30 µm, or equal to or greater than about 25 µm, or equal to or greater than about 20 µm.

[0095] 4. The inorganic particulate matter according to any one of paragraphs 1 to 3, having a d50 ranging from about 0.5 to about 3 μm, for example from about 0.5 to about 2, 5 µm.

[0096] 5. The inorganic particulate matter according to any one of paragraphs 1 to 4, having a d50 ranging from about 0.5 μm to about 1.5 μm, for example from about 0.75 μm to about 1.25 µm.

[0097] 6. Inorganic particulate matter according to any one of paragraphs 1 to 5, having a d50 ranging from about 1 μm to about 2.5 μm, for example from about 1.5 μm to about 2 µm.

[0098] 7. Inorganic particulate matter according to any one of paragraphs 1 to 6, having a d98 equal to or less than about 8 μm, for example, equal to or less than about 7 μm, for example , equal to or less than about 6 μm, for example, equal to or less than about 5 μm.

[0099] 8. The inorganic particulate material according to any one of paragraphs 1 to 7, wherein the inorganic particulate material is an alkaline earth metal carbonate.

[00100] 9. The inorganic particulate material according to any one of paragraphs 1 to 8, in which the inorganic particulate material is calcium carbonate, for example ground calcium carbonate (GCC).

[00101] 10. The inorganic particulate matter according to any one of paragraphs 1 to 9, having a slope factor ranging from about 35 to about 50, for example, ranging from about 40 to about 45.

[00102] 11. The inorganic particulate matter according to any one of paragraphs 1 to 10, in which the inorganic particulate matter is treated on the surface with a hydrophobicizing agent.

[00103] 12. The inorganic particulate matter according to any one of paragraphs 1 to 11, in which the inorganic particulate matter is treated on the surface with an aliphatic compound.

[00104] 13. The inorganic particulate material according to any one of paragraphs 1 to 12, in which the inorganic particulate material is treated on the surface with a fatty acid, or salt thereof, for example, stearic acid, or a salt thereof.

[00105] 14. The inorganic particulate material according to any one of paragraphs 8 to 13, in which the coating is substantially in the form of a monolayer.

[00106] 15. The inorganic particulate matter according to any one of paragraphs 1 to 14, having a moisture uptake after 48 hours equal to or less than about 0.2% by weight at 97% relative humidity, by for example, equal to or less than about 0.1% by weight at 97% relative humidity.

[00107] 16. The inorganic particulate matter according to any one of paragraphs 1 to 15, in which the % of particles smaller than 0.75 μm is equal to or smaller than about 40% by weight, for example, equal to or less than about 37% by weight.

[00108] 17. The inorganic particulate matter according to any one of paragraphs 1 to 16, in which the % of particles smaller than 0.5 μm is equal to or smaller than about 25% by weight, for example, equal to or less than about 20% by weight, for example, equal to or less than about 15% by weight.

[00109] 18. An inorganic particulate material having a d98 less than about 11 μm, or equal to or less than about 8 μm, in which the inorganic particulate matter does not withstand dry sieving or screening.

[00110] 19. The inorganic particulate matter according to paragraph 18, comprising equal to or greater than about 3 ppm of particles having a particle size greater than or equal to about 25 μm.

[00111] 20. The inorganic particulate matter according to paragraph 18 or 19, comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 40 μm.

[00112] 21. The inorganic particulate matter according to any one of paragraphs 18 to 20, comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 38 μm, or equal to or greater than about 30 µm, or equal to or greater than about 25 µm, or equal to or greater than about 20 µm.

[00113] 22. Inorganic particulate matter according to any one of paragraphs 18 to 21, having a d50 ranging from about 0.5 to about 3 μm, for example from about 0.5 to about 2.5 μm.

[00114] 23. Inorganic particulate matter according to any one of paragraphs 18 to 22, having a d50 ranging from about 0.5 μm to about 1.5 μm, for example, from about 0.75 μm to about 1.25 µm.

[00115] 24. Inorganic particulate matter according to any one of paragraphs 18 to 23, having a d50 ranging from about 1 μm to about 2.5 μm, for example from about 1.5 μm to about 2 µm.

[00116] 25. Inorganic particulate matter according to any one of paragraphs 18 to 24, having a d98 equal to or less than about 8μm, for example, equal to or less than about 7 μm, for example, equal to or less than about 6 µm, for example, equal to or less than about 5 µm.

[00117] 26. The inorganic particulate material according to any one of paragraphs 18 to 25, in which the inorganic particulate material is an alkaline earth metal carbonate.

[00118] 27. The inorganic particulate material according to any one of paragraphs 18 to 26, in which the inorganic particulate material is calcium carbonate, for example ground calcium carbonate (GCC).

[00119] 28. The inorganic particulate matter according to any one of paragraphs 18 to 27, having a slope factor ranging from about 35 to about 50, for example, ranging from about 40 to about 45.

[00120] 29. The inorganic particulate matter according to any one of paragraphs 18 to 28, in which the inorganic particulate matter is treated on the surface with a hydrophobicizing agent.

[00121] 30. The inorganic particulate matter according to any one of paragraphs 19 to 29, in which the inorganic particulate matter is treated on the surface with an aliphatic compound.

[00122] 31. The inorganic particulate material according to any one of paragraphs 18 to 30, in which the inorganic particulate material is treated on the surface with a fatty acid or salt thereof, for example, stearic acid, or a salt thereof.

[00123] 32. The inorganic particulate material according to any one of paragraphs 18 to 31, in which the coating is substantially in the form of a monolayer.

[00124] 33. Inorganic particulate matter in accordance with any one of paragraphs 18 to 32, having a moisture uptake after 48 hours equal to or less than about 0.2% by weight at 97% relative humidity, by for example, equal to or less than about 0.1% by weight at 97% relative humidity.

[00125] 34. The inorganic particulate matter according to any one of paragraphs 18 to 33, in which the % of particles smaller than 0.75 μm is equal to or smaller than about 40% by weight, for example, equal to or less than about 37% by weight.

[00126] 35. An inorganic particulate material having a d98 of less than 11 μm, and comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 25 μm.

[00127] 36. The inorganic particulate matter according to paragraph 35, comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 40 μm.

[00128] 37. The inorganic particulate matter according to paragraph 35 or 36, comprising equal to or more than about 3 ppm of particles having a particle size equal to or greater than about 38 μm, or equal to or greater than about 30 µm, or equal to or greater than about 25 µm, or equal to or greater than about 20 µm.

[00129] 38. The inorganic particulate matter according to any one of paragraphs 35 to 37, having a d50 ranging from about 0.5 to about 3 μm, for example from about 0.5 to about 2, 5 µm.

[00130] 39. Inorganic particulate matter according to any one of paragraphs 35 to 38, having a d50 ranging from about 0.5 μm to about 1.5 μm, for example, from about 0.75 μm to about 1.25 µm.

[00131] 40. Inorganic particulate matter according to any one of paragraphs 35 to 38, having a d50 ranging from about 1 μm to about 2.5 μm, for example, from about 1.5 μm to about 2 µm.

[00132] 41. Inorganic particulate matter in accordance with any one of paragraphs 35 to 40, having a d98 equal to or less than about 8 μm, for example, equal to or less than about 7 μm, for example , equal to or less than about 6 μm, for example, equal to or less than about 5 μm.

[00133] 42. The inorganic particulate material according to any one of paragraphs 35 to 41, in which the inorganic particulate material is an alkaline earth metal carbonate.

[00134] 43. The inorganic particulate material according to any one of paragraphs 35 to 42, in which the inorganic particulate material is calcium carbonate, for example ground calcium carbonate (GCC).

[00135] 44. The inorganic particulate matter according to any one of paragraphs 35 to 43, having a slope factor ranging from about 35 to about 50, for example, ranging from about 40 to about 45.

[00136] 45. The inorganic particulate matter according to any one of paragraphs 35 to 44, in which the inorganic particulate matter is treated on the surface with a hydrofibizing agent.

[00137] 46. The inorganic particulate matter according to any one of paragraphs 35 to 45, in which the inorganic particulate matter is treated on the surface with an aliphatic compound.

[00138] 47. The inorganic particulate material according to any one of paragraphs 35 to 46, in which the inorganic particulate material is treated on the surface with a fatty acid or salt thereof, for example, stearic acid, or a salt thereof.

[00139] 48. The inorganic particulate material according to any one of paragraphs 35 to 47, in which the coating is substantially in the form of a monolayer.

[00140] 49. Inorganic particulate matter in accordance with any one of paragraphs 35 to 48, having a moisture uptake after 48 hours equal to or less than about 0.2% by weight at 97% relative humidity, by for example, equal to or less than about 0.1% by weight at 97% relative humidity.

[00141] 50. The inorganic particulate matter according to any one of paragraphs 35 to 49, in which the % of particles smaller than 0.75 μm is equal to or smaller than about 40% by weight, for example, equal to or less than about 37% by weight.

[00142] 51. The composition comprising the inorganic particulate material according to any one of paragraphs 1 to 50.

[00143] 52. The composition according to paragraph 51, further comprising a polymer, for example selected from polypropylene (PP), polyethylene (PE) (for example low density polyethylene), polyvinyl chloride (PVC) , polyethylene terephthalate (PET), and any combination thereof.

[00144] 53. The composition according to paragraph 52, in which the composition is a polymer film, (for example, a lamination coating and/or, for example, a blown film, cast film, or extruded film), or a synthetic paper or raffia (eg raffia ribbon or raffia packaging).

[00145] 54. The composition according to any one of paragraphs 51 or 53, wherein the composition comprises at least about 1% by weight of the inorganic particulate material according to any one of paragraphs 1 to 50, for example, at least about 20% by weight of the inorganic particulate material according to any one of paragraphs 1 to 50.

[00146] 55. The composition according to any one of paragraphs 51 to 54, wherein the composition comprises at least about 40% by weight polymer, for example at least about 50% polymer by weight.

[00147] 56. The composition according to any one of paragraphs 53 to 55, in which the film has a thickness equal to or less than about 100 μm, for example, equal to or less than about 50 μm , for example, equal to or less than about 20 µm.

[00148] 57. The composition according to any one of paragraphs 53 to 56, in which the film has a thickness ranging from 5 μm to 100 μm, for example from about 5 μm to about 20 μm.

[00149] 58. The composition according to any one of paragraphs 53 to 57, in which the film is breathable, for example, in which the film has a moisture vapor transmission rate (MVTR) equal to or greater than than about 2000 gsm per day, for example from about 2000 to about 15,000 gsm per day.

[00150] 59. Use of inorganic particulate material according to any one of paragraphs 1 to 50 in a polymer composition (for example, in polymeric film, such as lamination coating, synthetic paper, raffia).

[00151] 60. The use, in accordance with paragraph 59, in which the polymeric is selected from polypropylene (PP), polyethylene (PE) (for example, low-density polyethylene), polyvinyl chloride (PVC), sodium terephthalate polyethylene (PET), and any combination thereof, for example, in which the polymeric film is biaxially oriented polypropylene (BOPP), or biaxially oriented polyethylene terephthalate (BOPET).

[00152] 61. The use in accordance with paragraph 59 or 60, in which the polymeric composition is a polymeric film, and the polymeric film is breathable.

[00153] 62. A method of producing a polymeric film, the method comprising: mixing (eg compounding) an inorganic particulate material according to any one of paragraphs 1 to 50 with a polymer; and casting the composite material into a film.

[00154] 63. The method, in accordance with paragraph 62, in which the polymer is selected from polypropylene (PP), polyethylene (PE) (for example, low-density polyethylene), polyvinyl chloride (PVC), sodium terephthalate polyethylene (PET), and any combination thereof.

[00155] 64. The method according to paragraph 62 or 63, in which the polymeric film is stretched to form a breathable film.

[00156] 65. Use of inorganic particulate matter in accordance with any one of paragraphs 1 to 50 as a cavitation agent.

[00157] 66. Use of inorganic particulate material, according to any one of paragraphs 1 to 50, in a polymeric film in order to reduce the release of inorganic particulate material from the polymeric film, and/or to reduce the deposition of inorganic particulate matter on the surface of the polymeric film.

EXAMPLES Example 1

[00158] A particulate material of ground calcium carbonate (GCC1) was prepared, and the particle size distribution was measured by Sedigraph. The results are shown in Table 1.

[00159] The GCC was treated on the surface with stearic acid. Differential Scanning Calorimetry (DSC) indicated a slight excess of monolayer coating above. Without wishing to be bound by theory, it is thought that this gives additional lubricity to the fine particles.

[00160] The surface-treated GCC1 was tested for moisture pick-up for 48 hours at a temperature of 20°C and a relative humidity of 97%. The surface-treated GCC1 was found to have a moisture uptake of less than 0.2% by weight.

[00161] Surface-treated GCC1 can be incorporated into a polymer without encountering processing problems, such as reduced operating time, despite the presence of some very coarse particles (larger than 25 μm).

Example 2

[00162] A particulate material of ground calcium carbonate (GCC2) was prepared and the particle size distribution was measured by Sedigraph. The results are shown in Table 2.

[00163] The GCC2 was treated on the surface with stearic acid. Differential Scanning Calorimetry (DSC) indicated a slight excess of monolayer coating above. Without wishing to be bound by theory, it is thought that this gives additional lubricity to the fine particles.

[00164] The surface-treated GCC2 was tested for moisture pick-up for 48 hours at a temperature of 20°C and a relative humidity of 97%. The surface treated GCC1 was found to have a moisture uptake of less than 0.1% by weight.

[00165] The surface-treated GCC2 can be incorporated into a polymer film without encountering processing problems, such as reduced operating time, despite the presence of some very coarse particles (larger than 25 μm).

Example 3

[00166] The surface coated GCC used in Example 1 above (GCC1) and another ground calcium carbonate surface treated with stearic acid, and having an approximate particle size distribution as shown in Table 3. (GCC3) were incorporated into Linear low density polyethylene produced by a blown film line at a thickness of 30 μm. These films were then stretched on a laboratory machine direction guideline between 3 and 5 times to simulate the industrial process. The films have a loading level of crushed calcium carbonate between 50 and 55% by weight.

[00167] A black cloth was held against the film surfaces during film stretching to remove any dust. The black tissues were then viewed under a microscope at 25x magnification. It was surprisingly found that no particles were visible on the black cloth used with the film incorporating GCC1, hence some particles are visible on the black cloth used with the film incorporating GCC3.

Claims (10)

1. Inorganic particulate matter, characterized in that it comprises: equal to or greater than 3 ppm of particles having a particle size equal to or greater than 25 µm; equal to or greater than 40% by weight of particles smaller than 0.75 µm; having a d98 less than 11 µm; and wherein the % of particles less than 0.5 is equal to or less than 25% by weight, wherein the inorganic particulate material is selected from an alkaline earth metal carbonate, wollastonite, kaolin, bauxite, talc, mica and combinations thereof. 2. Inorganic particulate material according to claim 1, characterized in that it comprises equal to or more than 3 ppm of particles having a particle size equal to or greater than 38 µm. 3. Inorganic particulate material according to claim 1, characterized in that it has a d50 ranging from 0.5 to 3 µm. 4. Inorganic particulate material according to claim 1, characterized by the fact that it has a d98 equal to or less than 8 µm. 5. Inorganic particulate material according to claim 1, characterized in that the inorganic particulate material is crushed calcium carbonate (GCC) or other alkaline earth metal carbonate. 6. Inorganic particulate material according to claim 1, characterized in that it has a slope factor ranging from 35 to 50. 7. Inorganic particulate material according to claim 1, characterized in that the inorganic particulate material is treated on the surface with a hydrophobicizing agent. 8. Inorganic particulate material according to claim 1, characterized in that it has a moisture uptake after 48 hours equal to or less than 0.2% by weight at 97% relative humidity. 9. Inorganic particulate material according to claim 1, characterized by the fact that the inorganic particulate material did not support dry sieving or screening. 10. Inorganic particulate material according to claim 1, characterized in that it comprises equal to or more than 3 ppm of particles having a particle size equal to or greater than 40 µm.